A White House senior advisor and son-in-law of President Donald Trump will testify before the Senate Intelligence Committee on Monday.

“The closed-door session sets up what could be one of the most highly anticipated interviews for lawmakers to date,” ABC News reports.

Questions at the closed door hearing will likely focus on Kushner’s contacts with Russian operatives and intermediaries during Trump’s 2016 campaign and subsequent transition to the presidential administration. Kushner allegedly violated federal law by failing to disclose many such contacts.

The interview will also focus on the June 9, 2016 meeting with Kremlin-linked attorney Natalia Veselnitskaya.

“Frankly, it’s a little bit unbelievable that neither the son or the son-in-law ever shared that information with their dad, the candidate,” ranking Democrat on the Senate Intelligence Committee, Senator Mark Warner (D-VA), told CNN Sunday.

“We don’t know because we don’t know really what happened at the meeting,” Warner said. “What we do know is Donald Trump Jr. did not tell the truth a variety of times.”

One other member to watch on the Intelligence Committee is veteran prosecutor Kamala Harris (D-CA).